Bumper



Dec. 31., 193s.l

Filed Dec. 5, 1934 V. P. WILLIAMS BUMPER 5 Sheets-Sheet 2 Dec. 3l, 1935. v, P W|| |AM$ 2,026,113

BUMPER Filed Dec.V 5, 1934 5 Sheets-Sheet 1 5 wwf Patented Dec. 31, 1935 UNITED STATES PATENT OFFICE BUlWPER Application December 3, 1934, Serial No. 755,821

22 Ciaims.

This invention relates to vehicle bumpers and is an improvement over the bumper construction shown in my prior Patent No. 1,957,515, granted May 8, 1934, as Well as a continuation in part of my copending application Serial No. 724,402, led May 7, 1934.

Both in my prior patent and in my copending application I have shown a bumper comprising a main or impact receiving bar and a back bar provided with spring arms that slidably engage the main bar. In my prior patent the main bar was provided with means acting to guide the spring arm in its sliding movement relative to the main bar. In my copending application there was provided in addition to the guiding means, resilient means which functioned to produce a frictional resistance to the sliding and vibratory movements of the spring arms.

It is accordingly an object of this invention to improve the construction, design, operation and efficiency of my bumper by the employment of various forms of resilient means designed not only to provide the necessary frictional resistance to the sliding and vbratory movements of the spring arms but also to add a supporting strength to the shock absorbing characteristics of the spring arms. i

More particularly it is an object of this invention to provide in a bumper comprising a l main bar and a back bar having at least one spring arm slidably engaging the main bar, a compressible spring means to be supported Within a housing and to be initially compressed therein to retain the spring arm in static frictional engagement within the main bar. y

Another object of this invention is to provide on the compressible spring means a bearing element adapted to have either frictional or antifrictional bearing `engagement with the spring A still further object of this invention is vto provide a compressible spring means of such capacity as to be capable oi undergoing additional compression upon movement of the spring arm as the same slides relative to the main bar.

It is another object of this invention that the sole connection ci the sliding portion of the springY arm with the main bar be constituted in the compressible spring means and the housing, pressure of said spring means on said spring arm being of such intensity as to obviate any movement er rattling of the spring arm on the main bar in the normal relationship of said parts.

These and other objects of this invention will become apparent as the description thereof given hereunder proceeds, reference being now had to the accompanying drawings in which like parts have the same reference characters and where- Fig. l is a plan view of a bumper with parts broken away showing the sliding ends of the spring arms of the bumper mounted Within a housing and one form of compression spring therein.

Fig. la is a partial rear elevational view of the bumper of Fig. 1 showing the housing.

Fig. 2 is a plan view of a bumper with parts broken away showing a housing connection for one spring arm.

Fig. 3 is a plan View of a. modified form of bumper construction showing a housing connection for a single spring arm carried by a vehicle frame part.

Fig. 4 is a detail partial sectional View taken cn line 4 4, Fig. la, of the housing connected to the main bar of the bumper, showing in detail one of the spring arms slidably mounted therein and a laminated spring cooperating therewith.

Fig. 5 is a partial sectional view of the connection of Fig. 4, taken on line 5 5, Fig. 4.

Figs. 6, 7, 8, 9, and 10 show in Views'similar to that of Fig. 4, modied forms of laminatedspring units and bearing elements.

Fig. 1l shows in a housing a modied form of a laminated leaf spring.

Fig. l2 is a View similar to that of Fig. 4 showinfr a laminated friction plate spring.

Fig. 13 is a view similar to that of Fig. 4 showing a modified construction employing helical coil springs.

Fig. 13a shows in a connection for a single spring arm a single helical coil spring.

Figs. 14, l5, 16, 17, 18, and 19 show in Views similar to that of Fig. 4 various modified forms of rubber springs.

Fig. 20 shows in an individual connection a rubber spring arranged at each side of a modiiied spring arm.

Fig. 21 shows in a connection similar to that oi 19 a volute spring construction.

Fig. 22 shows in a connection similar to that of Fig. 2l, a modified form of volute spring construction, employing an additional combined friction element wear piate and spring caps.

' Fig 23 is a sectional view taken on line 23-23, Fig. 22.

Fig. 24 shows in an individual connection a. sp'ral spring construction.

Fig. 25 shows in a view similar to that of Fig. 4,

a connection employing coil springs and a modifled housing construction.

Referring to Fig. l there is shown a bumper assembly comprising an impact or main bar I, the ends of which are pivotally connected or otherwise attached to the outer ends of the back bars 2 as at 3. The other or inner end portions of the back bars 2 are bowed inwardly to slidably engage the main bar I, said bowed portions of the back bars constituting spring arms li. The bumper assembly Vis attached to the frame horns 6 in any desired manner as by the bolts 'I connecting the back bars 2 to the ends of the frame horns.

As the prime object of this invention is to produce a frictional resistance to the sliding and vibratory movements of the spring arms i on the main bar I as impacts are delivered thereon it is necessary to provide a resilient means of one form or another acting against the spring arms to provide the necessary pressure on the same for thefproduction of the above indicated frictional resistance. AccordinghT in the form of bumper assembly shown in Fig. l, there is provided a retaining member or housing I, that is adapted to receive therein the free end portions of the spring arms 4 that slidably engage the main bar I. Positioned between the housing and the spring arms 4 are spring units Ii, that are placed under an initial compression within the housing Ii) which is secured to the main bar I by the bolt I2 in the manner readily apparent.

The specific spring means II and details of construction pertaining thereto as well as other i forms of modified spring means employed in this relationship will be described in detail hereinafter.

In some cases it will be necessary to employ an individual retaining member o1' housing for the end of a spring arm. Such a construction is shown in Fig. 2 where the sliding end of the spring arm i is positioned within the housing iii which may be secured to the rear of the main bar I by fastening elements i5. A similar spring II is mounted within the housing Ill under an initial compression and functions as described above to retain the spring arm 4 in frictional engagement with the main bar I.

The housing and spring connection such as shown in Fig. 2 is equally adaptable for use as a connection for the end of a spring arm such as I6 carried by the main bar Il, that slidably engages the bumper supporting means I 8 carried by the frame horn IS, all as clearly shown in Fig. 3.

As described above with reference to Figs. l, 2, and 3 it is seen that the slidable portions of the spring arms are retained at all times in their sliding engagement with the main bar or supporting member oi the bumper, by the connection comprising the spring units II supported in the housing iii. It is accordingly desired that it be understood that this spring unit connection as well as any one of the various modied forms thereof to be described in detail hereunder may l be employed for this purpose either in a double connection such as shown in Fig. i, or in the individual form of connections shown either in Fig. 2 or Fig. 3.

In the connection shown in Fig. I, as well as that in Figs. 2 and 3, the spring unit I i employed is a bowed leaf spring preferably formed of a plurality of laminations. Such a type of spring is shown in the construction illustrated in Figs. 4 and 5. Fig. 4 being a plan view of the connection with a portion of the top wall of the housing removed as on line @-4, Fig. la. In this form of double connection for two spring arms, as well as in all other double connections to be described hereinafter, in View of the identical nature of the spring units employed therein, only one side will be described. The housing or retaining member It! is preferably made of sheet metal and is formed as a tubular member having four sides with the ends open as at 2G. The housing I@ is secured to the main bar i by the bolt i2 there being pro- 10 vided a spacer sleeve 2i within the housing through which the bolt is passed to prevent buckling of the Walls thereof. Disposed within the housing it adjacent the wall 22 is a wear plate 23 that may be retained in position by being 15 clamped to the wall 22 by the spacer sleeve 2I. 'I'his wear plate 23 may be of any suitable metallic material, brake band or any other friction material. In some cases this wear plate may even constitute a rubber lining. Slidably engaging the wear plate 23 are the end portions of the spring arms 4 carried by the back bars 2, see Fig. 1. The spring unit II is made up of a plurality of laminations each formed from spring steel, bowed and nested together to form the complete spring. 25 Securing all the laminations together is a rivet 25, having a large head 26 on the upper part of the spring. Each of the laminations of the spring I I are provided with oppositely disposed notches 2'! that register with each other on each side and 30 receive therein the bosses 28 struck out of the side walls 29 of the housing l0, as clearly sho-wn in Fig. 5. This engagement of the spring I I with the bosses 23 when the spring II is mounted in operative position within the housing I0 is to 35 prevent bodily longitudinal movement of the spring I I as the spring arms li move inwardly under impacts delivered to the main bar, which movement will further compress the spring II, the notched spring II then being guided on the bosses 28. The rivet head 2G on the spring II acts as a bearing element in its engagement with the spring arm 4, thus removing all wear from the spring II itself.

The spring II when operatively mounted Within 45 the housing I Il is preferably placed under an initial compression which is suiiicient to exert the required amount of pressure on the spring arm li and wear plate 23, in order to produce the necessary frictional resistance therebetween to the sliding and vibrato-ry movements of the spring arms li relative to the main bar I. As will be apparent a certain amount of friction will also take place between the rivet head or bearing element 26 and its associated spring arm 4'. 55

While in the construction shown in Fig. 4, a wear plate 23 is shown employed, it is to be understood that in this case as well as in all the other modications described hereunder, its use is entirely optional; the same may be dispensed 60 with if so desired, in which case the spring arms 4 will bear directly either on the wall 22 of the housing or on the rear of the main bar I itself.

In the connection shown in Fig. 6, the same form of housing I0, bolt I2, spacer sleeve 2I, and 65 wear plate 23 is employed in conjunction with the main bar I. n The spring unit mounted within the housing comprises the laminated leaf spring 30, provided centrally on the upper side thereof with an upstanding U-shaped bracket`3I and on the 70 lower side thereof with a depending stud 32 each rigidly connected to the spring S by the common rivet or other suitable fastening means 33. `Attached to the rear wall of the housing It opposite that portion of the spring arm 4 that is in con- 75 tact With the Wear plate 23 is a cylindrical guide 314 adapted to receive in guiding relation the stud 32 of the spring 35 which parts while permitting compression of the spring 3l) in a direction transverse to the housing will act to prevent bodily movement thereof in all other directions. Rotatably mounted on the arms 35 oi the U-bracket 3 I is a roller 35 which is adapted to have bearing engagement with the spring arm d, and through ther action of the spring 3!! will exert the required pressure on the spring arm 4 necessary to produce the frictional' resistance between the same and the Wear plate 4, to the sliding movement of said spring arm. In this embodiment the roller 36 Will' present very little frictional resistance, if any, to the movement of the spring arm 4 there-` on. If desired, the open ends 2li of the housing I0 may be provided with U-shaped closure elements 31, the arms of which are provided with recesses 38 adapted to have a snap-action with projections (not shown) found on the side Walls of the housing It.

The embodiment of the connection shown in Fig. 7 differs from that of Fig. 6 only in the form of guiding means for the laminated leaf spring 40. In this case the spring 4s is provided centrally, and on the lower side thereof with a U- shaped bracket 4i, which along with the upper U-shaped bracket 3l is rigidly fastened to the spring 40 by means of the rivet (i2. The side arms 43 of the U-bracket 4I are bi-furcated as at 44, and are adapted to have guiding engagement with the pin or bolt 45 rigidly secured to the side walls of the housing iii. It is thus seen that while the spring 4!) and its associated parts are permitted the movement incident to the compression of the spring 40, the same cannot move longitudinally of the housing Iii. The bracket 3l and roller 35 are identical in all respects with that shown employed in Fig. 6'. Between the Wear plate 23 and the wall 22 of the housing I!) there may be provided as showin a rubbed pad 46, which provides not only a resilient support to the Wear plate 23 and incidentally the spring arms 4, but also possesses the characteristics of a sound deadening and vibration absorbing medium. To close the open ends 2ty of the housing III there may be provided a flexible boot 4l of any suitable material. It is to be understood that this flexible boot 41 as wellas the closure clips 3'! shown in Fig. 6 are intended for use with the housings in any of the preceding forms of connections described above as well asin all the fols lowing forms to be described hereinafter.

It is also to be understood that the use of the rubber pad 4E is not limited to the showing in Fig. '7, as said rubber pad may be employed with any of the wear plates 23 used in any of the connections disclosed herein.

In Figs. 8 and 9 there is shown a similar form of spring unit and bearing means as that shown in Figs.` 6 and 7. In this particular form the laminated spring 53 has secured centrally on the upper portion thereof by the rivet 5I, a U-shaped bracket 52. The bracket 52 as shown in Fig. 9 is of a width greater than that of the spring 53 and is formed at the ends thereof with projections 53 adapted to be positioned Within the pockets 54 formed in the side walls 29a of the housing IB, for guided movement therein. This construction will permit the spring 5t to be compressed but will prevent bodily movement thereof in directions lengthwise of the housing. Fitted for rotative movement on the sides 55 of the bracket 52 are the studsr 55 of the eccentric 5l adapted to have bearing contact with the spring arms 4. The normal position of the eccentric 5'! relative to the spring arm 4 is as shown in Fig. 8 that is, with its shortest radius arranged between the spring arm 4 and its axis of rotation. Preferably both 5. the contacting surfaces of the spring arm 4 and the eccentric are serrated as atv58 and 58a to insure that no slipping occurs between the two.

In view of the initial compression und-er which the spring 53 is placed when mounted in operal0 tive position, the force that the same exerts upon the spring arm 4 will produce the necessary frictional resistance to the sliding movements of said spring arm 4 on the wear plate 23, in the manner heretofore explained. In addition, as the spring 15T arm 4 moves inwardly, under impacts delivered to the main bar I, said spring arm i will cause the eccentric 5i to rotate in a clockwise direction, thus further compressing the spring arm 50 and increasing the pressure acting in the spring arm 4 20 s with a consequent production of an increase in said frictional resistance.A This increase in frictional resistance is proportional to the inward movement of the spring arm 4, and also to the degree of impact on the main bar I. Upon return 25y movement of the spring arm 4, there will be a gradual reduction in the force bearing on the spring arm as the eccentric is rotated in a counter clock-wise direction, thus permitting the parts of the bumper to resume their normal relative 30.

positions Without rebound, noise and chatter.

In the modified form of construction shown in Fig. l0, the laminated spring 63 is provided centrally en its upper side with a cup-shaped race member Si, secured to the spring by the rivet 62. 3:5` l

ositioned within the race-member 6I and bearing against the spring arm 4 are anti-friction ball y or roller bearings The spring is of the same form as spring I I, Figs. 4 and 5, and is provided with the oppositely disposed slots 21 in 40'.

which are positioned the housing bosses 28, adapted as described above, to prevent movement of the spring Se' longitudinally of the housing I0.

With reference to the laminated spring employed in each of the modified forms of connecal tions shown in Figs. l to 1G, inclusive, it must be understood that I am'not to be limited to the use of a laminated leaf spring, as it may be desirable in many cases to utilize only a single bowed leaf spring element, to be associated with 5o.;

any of the forms of bearing elements shown in said figures and as described above.

The connection shown in Fig. 11, discloses a modified form of laminated spring 10, mounted within an individual housing 'I I, of the type such as at I4, see Figs. 2 and 3. In this case the spring Il? is made up of a plurality of nested lamina-tions, somewhat oval in shape with one side thereof provided with a re-entrant portion, so

to dene spaced contracting portions 'l2 and to: i3, adapted to engage the slidable end of the spring arm i positioned within the housing ll. The contacting portion i3 of the spring is adja cent one end thereof, the other end of the spring being rounded as at i4 and adapted to normally et.:

placed by helical coil springs.

the assembled relation of parts the spring 'Ill is placed under an initial compression sufficient to exert the required force on the spring arm 4, necessary to produce the frictional resistance to the sliding movement of the spring arm on the main bar I. While in the connection shown in Fig. l1, no wear plate has been employed between the spring arm 4 and main bar I, such a wear plate as 23, see Fig. 4, may be provided if desired, as yheretofore explained.

In Fig. 12, there is shown in a double housing I0, a friction plate spring construction 8B. rIfhe spring Sii is made up of a plurality of laminations 8|, each of convex-concave formation and nested so as to have the concave portions 82 intermediate the convex portions 83, with the convex portions on the upper side of the spring. The laminations are securely held together by the rivet 84 provided with a conical head B5 adapted to seat in the conical recess 8S formed therefor in the rear wall of the housing lil, so as to prevent bodily movement of the spring 8S longitudinally of the housing IQ as the'spring arm d slides thereover. The position of the spring 8|! is then such that the convex portions thereof will engage the spring arm 4 at spaced points 8l, the ends 88 of the spring 8@ slidably engaging the rear wall of the housing I0. It is of course understood that the spring 83 is normally under an initial compression, similarly as the laminated springs above described.

The spring arm connection shown in Fig. 13 is substantially similar to that shown in Fig. 7, except that the laminated leaf spring ill is re- The bracket 3|, rotatably supporting the roller 36 is centrally supported on the upper surface of a spring cap 90 which also supports on its lower surface the guide bracket 4I, both brackets 3| and 4I being securely fastened to the spring cap by the rivet 42. The spring cap 90 is guided by the bracket 4I on the pin 45 in the manner as described above with reference to Fig. 7. Arranged between the spring cap 90 and the rear wall of the housing I0 are a pair of helical coil springs 9|, that are retained in this operative position by the bosses 92 in the spring cap 90, and the bosses S3 formed on the housing I0. As in all the other forms of springs described above, the coil springs 9| are similarly placed under an initial compression when mounted in their operative position within the housing III. For greater stability it may be desirable to replace the coil springs 9| with conical coil springs, the convolution of greatest diam. eter being seated on the rear wall of the housing III.

In Fig. 13a the U-bracket Sla is provided with a centrally depending boss 95 that centers the upper end of the conical spring 96, the lower end thereof being seated in the recess 91 provided therefor in the rear wall of the housing 98 which may be secured to the main bar I or other supporting element by the welds 99 or any other suitable fastening means. The bracket 3|a rotatably carries the roller 35 which bears on the spring arm 4. The bracket Sla may be formed in the manner in which the bracket 52, see Fig. 8, is formed for guiding engagement with the side wall of the housing 98, formed with guides I 00, such as 54 (see Fig. 8). The single helical spring unit employed in Fig. 13a may equally as well be adapted in the connection shown in Fig. 13, as a replacement for the double helical coil springs therein.

It has been found that in some cases the use of metallic springs in the connections as above set forth may be replaced by non-metallic springs preferably formed of rubber. Such use of rubber spring elements is shown in Figs. 14 to 19 inclusive. 5

In Fig. 14, the slidable end 4a of the spring arm 4 is shown of tapered wedge-like formation and engages the wear-plate 23 disposed within the housing Ill. The housing III is connected to the main bar I by means of the bolt I 2 which is provided with the spacer sleeve 2|. Positioned on each side of the bolt I2 is a rubber block IIII that is locked against movement outwardly of the housing by the abutment |02 which may constitute an integral part of the housing IIJ. Inward 15 movement of the rubber block IlI is prevented by the abutment member |03 which is securely held in place by the bolt I2 and spacer sleeve 2| in the manner clearly shown. The rubber blocks IIlI may be of a width slightly less than the in- 20 ternal width of the housing IQ. The front face of the rubber block IBI is inclined rearwardly in a direction outwardly of the housing IEI and has tted thereon a bearing plate |04 which, as shown, is provided with corrugations |85 arranged trans- 25 versely of said plate. The bearing plate |05 terminates at its inner end in a depending flange |95 that is adapted to abut in sliding engagement the spacer sleeve 2|.

In the assembly of the housing ID and rubber blocks IIII as a connecting means for the sliding ends 4a of the spring. arms 4, each rubber block is placed under an initial compression, holding the spring arm 4 in friction tight engagement with the wear plate 23. When the spring arm 4 is deflected as a result of the main bar receiving an impact, the wedge-like end 4a of the spring arm will be caused to force its way farther into the housing IIJ, which movement will cause the rubber block IElI to be further compressed as the 40 bearing plate |84 is forced towards the rear wall of the housing I 0. If desired the corrugated bearing plate |04 could be replaced by one having a smooth uninterrupted surface, in case it is desired to increase-the area of frlctional contact 45 of the same with the spring arm end 4a. It is preferable, however, in order to insure freedom of movement of the spring arm on the bearingr plate, to have the same corrugated as shown.

The connection shown in Fig. 15 is provided 50 with a similar form of housing I Il attached to the main bar I by the bolt I2. Slidably disposed within the housing II) are the end portions 4b of the spring arms 4, that frictionally engage the wear plate 23. The rear wall of the housing II! is pro- 55 vided with pockets or recessed portions I I in which are seated the rubber blocks III, which preferably are of a width slightly less than the distance between the side walls of the housing. The rubber block I I I is molded in the form shown G0 in Fig. 15, that is, in the form of a parallelogram having the front face II2 laterally oiset with respect to the rear face IIS disposed within the pocket III?. Vulcanized or otherwise secured to the face II2 of the rubber block I II is a bearing 65 cap |I4 adapted to contact the slidable portion 4b of the spring arm which arm is provided with the projection ||5 that extends in abutting engagement with the outer edge of the bearing cap II4. As in all other forms of connections de- 70 scribed, the rubber blocks I I I are under an initial compression, which is sufficient to produce the required frictional resistance to the sliding movement of the spring arm.

In View of the projection IIE engaging the 75 bearing cap I I4, the movement of the spring'arm 4 inwardly of the housing I0 will cause a simultaneous movement of the bearing cap ||4 in the same direction, which movement will act to further compress the rubber block as it is deformed into the rectangular shape indicated by the dotted lines. It is thus apparent that the center of pressure indicated by the arrow P eX- erted by the rubber block on the spring arm portion 4b, moves with .said spring arm portion as the same slides along the wear plate 23 in the production of the frictional resistance required to absorb the shocks of impact. Return movement of the spring arm 4 is aided by the force stored in the rubber block as the same returns to its normal position, in the manner readily apparent.

A form of connection wherein there is employed a rubber block on each side face of the slidable spring arm is shown in Figs. 16 and 17. In this form of connection the housing lila is preferably made of a rather rigid construction and cornprises the side Walls |20 and rear wall |2I, the end portions of said rear wall being formed with inturned ends |22, for a purpose to be hereinafter described. Arranged centrally within the housing IIJa is a spacer element |23, formed of the two anged sections |24, which when welded together as at |25 form a cylindrical opening |25a for the reception of the bolt 2, which secures the housing to the main bar I. The spacer element bridges the side walls |20 of the housing and is rigidly secured thereto in any desired manner, for example by the welds |26, thus obviating any tendency of the housing walls to buckle as the same is attached to its supporting element.

Disposed Within the housing I0gd on each side of the spacer element |23 are the rubber blocks |21 and |28, separated by the U-shaped bearing clip |20. The bearing clip |29 comprises a bearing plate I3@ engaged by the rubber block |21 and a spaced bearing plate |3| engaged by the rubber block |28, the bearing plates |30 and |3| being connected together at their inner ends as at |32, the outer ends of said bearing plates being provided respectively, with the flanges |33 and |34, which flanges respectively abut the outer ends of the blocks |21 and |28. The inner ends of the rubber blocks |21 and |28 are normally in abutting engagement with the spacer element |23, see Fig. 17.

Extending partially within the bearing clip |20 is the slidable end portion 4c of the spring arm 4, the faces of which are adapted to have friction bearing engagement with the bearing plates |30 and |3|. As stated, the rubber blocks |21 and |28 are disposed on each side of the bearing clip |29, said blocks being initially of such a size that when assembled within the housing and connected to the main bar said rubber blocks will be placed under an initial compression so as to tightly force the bearing plates |30 and |3| against the side faces of the spring arm 4C, with a force sufficient to prevent vibratory movements thereof. Movement of the spring arm portion 4c inwardly will be frictionally resisted as will be apparent. Relatively large movements of the spring arm 4 will cause the end thereof to engage the portion |32 of the bearing clip |20, whereupon the saine will move inwardly, the flanges |33 and |34 thus compressing the rubber blocks |21 and |28, in the longitudinal direction of the housing |0a. Withdrawal of the bearing clip 29 from the housing and its associated rubber block is prevented by the flange |34 thereof engaging the inturned end |2-2 of said housing.

In Fig. 18, the housing I0 is provided at the ends thereof with abutments or flanges and -is secured to the main bar by the bolt |2. Dis- 5 posed within the housing l0 and in engagement with each of the flanges |40 is a single rubber member |4| provided at each end thereof with an upright substantially cylindrical projection |42. On the upper surface of each of said projec- 10 tions |42 is secured a bearing cap |43 adapted to frictionally engage the sliding portion of the lspring arm 4. The rubber member |41 is formed so as tosnugly engage the walls of the housing l5 as Well as theV iianges |40 and forms a resilient 15 base for the rubber projections |42 integral therewith, said projections being of a diameter at least equal to the width of the spring arm 4. As in all other previous cases the rubber projections |42 are under an initial compression and func- 20 tion in much the same manner as some of the other spring units as heretofore described. A washer |44 is provided between the spacer sleeve |45 and the rubber element |4I.

In Fig. 19, a rather different form of rubber 25 spring is employed. In this case the housing AIl) is of the same form as that shown in Fig. 18 and is provided with the end walls or anges |40. The rubber block is molded in the form of a foursided pyramid and is provided with a central 30 opening |5|. The base of the rubber block |50 is preferably made square with the sides equal to the internal width of the housing, there being a block arranged at each end of the housing |0 in abutting engagement with the flange |40. To 35 retain the rubber blocks y|50 in position, a sheet metal spacer |52 provided with the vertical flanges |53 is disposed between said blocks and is locked in place b-y the spacer sleeve 2| and bolt |2 which bolt also secures the housing I0 and its associ- 40 ated parts to the main bar Positioned within the opening |5| of each rubber block |50 is a wear button |54, the head of which is adapted to bear on the end portion of the spring Varm 4 that slidably engages the Wear plate 23. This 45 form of rubber block 50, which is under compression when in operative assembly will through the medium of the wear button |54 exert a high centralized pressure on the spring arm 4, and functions in much the same manner as the form 50 of laminated spring shown in Fig. 4. It is not necessary that the rubber block |50 Ashown pyrami-dical in form be made in such a shape as a cone formation thereof will function equally as well. 55

The form of individual connection shown in Fig. 20, shows a rubber spring or cushion arranged on each side of a modified form of spring arm.

Thevslidable end portion of the spring arm 4 is formed with a reversely 'bent bowed portion 60 4d, the end of which slidably engages the spring arm 4 as at |60. The loop-like end of the spring arm 4 is thus provided with two friction sliding surfaces |6| and |62. The housing |63 is of boxforrnation, one side of which is open as at |64 65 to accommodate the movement of the spring arm 4, and is secured to the main bar or other supporting element of a bumper by the rivets |65. Arranged within the housing |63 on each side of the looped end |65 of the spring arm 4 are rub- 70 ber blocks |61 and |68 of a size toy substantially snugly fit within the area dened by said housing. Each of the rubber blocks |61 and |68 are provided with transverse openings |69 to permit deformation of the rubber blocks.

Between the of the bolt I2. Arranged Within the interior of on the spacer element |52.

rubber blocks and the surfaces IGI and |62 of the spring arm 4 are wear or bearing plates |10 and III..

In the assembled relationship of the parts, the rubber blocks |61 and |58 are placed under an initial compression that produces a friction tight engagement of the looped end |06 of the spring arm 4 with the wear plates |10 and I'I I, the force of this compression being present at all times as the looped end |60 slides between the wear plates. With this construction it is obvious that the frictional resistance to the sliding movement of the spring arm 4 has been substantially doubled. In order to adjust the degree of compression, an adjusting screw such as I'|2 may be provided. It is also obvious that the looped end |86 of the spring arm 4 possesses a definite spring action under the forces exerted thereon by the compressed rubber blocks |61 and |08, which spring action will in itself produce a frictional resistance to the sliding movement'of the looped end |66. It is to be understood that this form of connection While shown for use With a single spring arm, may equally be adapted for use as a connection for two spring arms, such as in Fig. 4.

The connection shown in Fig. 21 is similar to that shown in Fig. 19, except that the rubber blocks |50 are replaced with volute springs H5. that are each similarly retained in place by the flanges |40 on the housing I0 and the anges |53 These flanges while normally straight may be ,formed curved so as to snugly engage the outermost convolution |16 of the volute spring |15. Disposed within the innermost convolution I'I'I is a wear button |544,

' the head |55a thereof engaging the spring arm 4.

In view of the stability and great capacity inherent in volute springs their use in a connection ing |80 is rectangular in cross-section and of a length suficient to accommodate the sliding ends of the two spring arms 4, the wall I8I and |82 of wider width being disposed parallel to the main bar I to which said housing is attached by means rected tongue I 81, struck out from the spring arm 4.

Slidably fitted for transverse movement between the tongues |88 and |81 is a disc-like spring capi |88 formed with diametrically opposed projecting tongues |89 slidably contacting the inner faces of the tongues |88 and I8?. Similar diamet- `rically opposed tongues |00 arranged at right angles to the tongues |80 are formed on the spring cap |88, the diameter of which is such that the tongues I 90 thereof are adapted to have sliding engagement with the transverse side walls of the housing |80 as the same moves simultaneously with the spring arm end portion 4e in its movement within the housing. Seated on said spring cap |88 and centered by the tongues |89 and |90 thereon is the volute spring |0|, the smallest 5 convolution thereof being adapted to bear against the spring arm portion 4e, said volute spring IBI being wholly confined between the spring arm portion 4e and the spring cap |88 engaged thereby, as clearly shown in Fig. 22. From the con- 10 struction just described it is seen that both the slidable end portion 4e of the spring arm 4 and the cap |88 are urged into frictional engagement with the wear plates |33 and |84 for all positions of the same, with suiiicient pressure to l5 produce a high degree of frictional resistance to the sliding movement of the spring arm. Preferably the volute spring |8I when placed in operative position is practically compressed to its maximum limit as shown in Fig. 22, which in view of the characteristics thereof will in a minimum of space store a maximum of compressive energy.

The connection shown in Figs. 22 and 23, in View of the employment of the volute springs |9| is of remarkably compact form and possesses a maxi- 25 mum of shock absorbing properties in view of the additional friction producing surface presented by the sliding spring cap |83, which renders the connection particularly adaptable for heavy duty bumpers.

While in this form of connection shown in Figs. 22 and 23 a volute spring has preferably been employed it is to be understood that the same may be replaced by any type of resilient means desired as for example, rubber, leaf springs, disc springs, coil springs etc.

In Fig. 24 there is shown an individual connection for the slidable end portion of a spring arm in which a spiral spring is employed.

Attached to the main bar in any suitable 40 manner is the housing 200 provided with an opening 20| through which the end portion 4f of the spring arm 4 extends into the housing for sliding engagement with the wear plate 23. A p-in 202 transversely disposed within the housing is rigidly supported by the side walls thereof in nonrotating engagement and is provided with a longitudinal groove or recess 203. Mounted o-n the pin 202 in surrounding relation thereto is the spiral spring 204, one end 205 of which is adapted to seat within the groove 203 for locking engagement with the pin 202. The spiral spring 204 is made of iiat spring stock, rectangular in cro-sssection and wound into spiral form in the manner well known in the art. One end 205 as indicated above is adapted for locking engagement with the pin 202, the other end of the spiral spring being formed into a loop 206 as clearly shown. In the assembly of the parts of the connection the spiral spring is initially stressed by winding the spring in a clock-wise direction, and upon the provision of sufcient tension thereon the looped end 206 is slipped over the end of the spring arm 4 for locking engagement therewith.

In the normal relationship of parts, the energy C5 stored in the spiral spring 204 will tend to unwind the same with the consequent production of an endwise force indicated by the arrow F and a normal force indicated by the arrow f on the slidable endllf of the spring arm 4. These two forces are sufficient to tightly press the spring arm end 4f against the wear plate 23 to produce the required frictional resistance to the sliding movement thereof.

This use of a spiral spring will impart to the bumper an added resiliency that reinforces the resiliency of the spring arms ll in the absorption of shocks and impacts received by the bumper.

In Fig. 25, the housing 2 lo is formed preferably as a casting having the front and rear walls 2 Il and 262 and the side walls 2l@ all joined by the central partition 2M provided with the bore 2l5 through which the bolt E2 extends to secure the housing 2l!) to the main bar I or other support member. The rear wall is provided with an opening 2l@ on each side of the bolt I2 for a purpose to be hereinafter described. The spring arms 4 each extend within the housing iil and engage the front wall 2l i thereof. To retain the slidable end portions of the arms in frictional engagement with the wall 2li coil springs fi'i are provided which as shown bear at one end against the spring arm il. The other ends of the coil springs E i ll are seated in cups 2 i 3 carried by the rear wall 2li?. The cups ZIB may either be formed integral with the housing 2H] or may be made separable as shown in order to facilitate assembly of the coil spring therein. As shown the cup 2I8 has a threaded engagement as at EIS With the opening 2 i6, which threaded engagement may be utilized to adjust the compression of the coil spring 2H.

In the form of connection shown in Fig. 25, no bearing element has been sho-Wn mounted on the coil spring 2H, the same bearing directly on the` spring arm Li. The construction also lacks a Wear plate such as 23 as heretofore described, the spring arm l directly engaging the front wall 2 l l. It is to be understood howeve-r, that if so desired both the bearing element and wear plate may be utilized. Also, the coil spring 2 i 'l may be replaced either with a volute spring or rubber blocky in fact any type of spring suitable for use in this housing construction as may be desired.

The invention having been described as above set forth, what I claim is:-

l. In a bumper provided with a spring arm member having an end portion slidably engaglng a surface on a supporting element, a housing member carried by said supporting element completely enclosing said spring arm end portion, a resilient unit arranged between said spring arm member and said housing member and held solely by one of said members against bodily movement with respect thereto.

2. In a bumper provided with a spring arm member having an end portion slidably engaging a surface on a supporting element, a housing member carried by said supporting element completely enclosing said spring arm end portion, a resilient unit arranged between' said spring arm member and said housing member and held solely by one of said members against bodily movement with respect thereto, said housing member defining Walls so constructed and arranged .as to surround at least three sides of said spring arm end portion, the Wall coextensive 'with said spring arm end portion being laterally spaced therefrom to accommodate said resilient unit and to permit movement of said spring arm end portion within said housing member.

3. In a bumper provided with a spring arm having an end portion thereof slidably engaging a surface on a supporting member, means carried by said supporting member completely enclosing said spring arm end portion, a resilient unit arranged between said spring arm end portion and said enclosing means and constituting the sole connecting medium for retaining said spring arm end portion in frictional bearing engagement with said surface on said supporting member.

4. In a bumper provided with a spring arm having a portion thereof adapted to frictionally 5 slidably engage a surface on a supporting member, a resilient unit, a bearing element mounted on said unit arranged in normal abutting relation to said spring arm portion, and means retaining said resilient unit and bearing element l0 in operative position with relation to said spring arm.

5. In a bumper, a pair of elements one of Which is provided with a surface adapted for slidable movement on a surface of the other, means holding said elements in static frictional engagement comprising a retaining member mounted on one of said elements, a resilient unit supported under compression by said retaining member and reacting normally against the other tain said operative frictional engagement between the spring elements and said supporting member.

'7. In a bumper comprising a spring arm and a supporting member, a housing carried by said member provided with an opening at one end 46V thereof intoI which an end portion of said spring arm projects for sliding engagement with a surface on said supporting member, and resilient means mounted within said housing and reacting normally against said spring arm end portion to produce a frictional resistance to the sliding movement thereof.

8. In a bumper comprising a pair of spring arms arranged in opposed relation, a supporting member therefor, a housing carried by said mem- D0' ber provided with an opening at each end through which an end portion of an adjacent spring arm projects for sliding engagement with a surface onsaid supporting member, and resilient means mounted within said housing and reacting normally against each of said spring arm end portions to produce a frictional resistance to the sliding movement thereof.

9. In a bumper comprising a spring arm and a supporting member, a housing carried by said member provided with an opening at one end thereof into which an end portion of said spring arm projects for sliding engagement with a surface on said supporting member, and resilient means Within said housing held thereby against bodily movement with respect thereto and reacting normally against said spring arm end portion to produce a frictional resistance to the, sliding movement thereof. H 10. In a bumper comprising a spring arm having a portion thereof adapted to frictionally slidably engage a surface on a supporting. member, a retaining member carried by said supporting member, a spring formed of elongated flat stock supported by said retaining member and bear-- ing on said spring arm for producing a frictional resistance to the sliding and vibratory movements of said spring arm, and means locking said spring to said retainer to prevent relative movement therebetween.

11. In a bumper, a main bar, a back bar having an end thereofslidable relative to said main bar, a housing secured to said main bar and enclosing said back bar end, a leaf spring supported in said housing and arranged to normally bear on said back bar to produce a frictional resistance to the sliding movements thereof, said leaf spring and said housing having a co-acting relationship whereby compressive movements of said spring is permitted and bodily movement thereof relative to said housing is prevented.

Vi2. In a bumper, a supporting member, a housing secured thereto, a supported spring member having an end thereof projecting into sai-d housing and adapted to have slidable movement therein, a bowed leaf spring supported within said housing and arranged to bear normally on said spring member to produce a frictional resistance to the sliding movements thereof, and means associated with said housing and cooperating with said leaf spring to permit compressive movements of said leaf spring while preventing bodily movement thereof relative to said housing.

13. In a bumper, a main bar, a housing secured thereto, a back bar having an end thereof projecting into said housing and adapted to have slidable movement therein, a laminated leaf spring supported within said housing, bearing means associated with said spring and arranged to engage said back bar to produce a frictional resistance to the sliding movements thereof, said spring and said housing having a co-acting relationship whereby compressive movements of said spring is permitted and bodily movement thereof relative to said housing is prevented.

14. In a bumper, a main bar, a housing secured thereto, a back bar having an end thereof projecting into said housing and adapted to have slidable movement therein, coil spring means supported within said housing and arrange-d to bear normally on said back bar to produce a fricti-onal resistance to the siiding movements thereof, said housing providing means whereby compressive movements of said coil spring means is permitted and bodily movement thereof relative to said housing is prevented.

15. In a bumper, a supporting element, a housing secured thereto, a supported spring element having an end thereof projecting into said housing and adapted to have slidable movement therein, a wall on said housing arranged opposite and in spaced relation to said spring element, coil spring means under compression bridging the space between said housing wall and said slidable spring element to produce a frictional resistance to the sliding m-ovements thereof, and centering means on said housing wall for said coil spring means to seat the same whereby compressive movements of said coil spring means is permitted and bodily movement thereof relative to said housing is prevented.

16. In a bumper, a main bar, a housing secured thereto, a back bar having an end thereof projecting into said housing and adapted to have slidable movement therein, coil spring means supported within said housing normal to said back bar end, bearing means associated with said coil spring means and arranged to engage said back bar to produce a frictional resistance to the sliding movements thereof, said housing providing means whereby compressive movements of said coil spring means is permitted and bodily movement thereof relative to said housing is prevented.

17. In a bumper comprising a pair of spring arms arranged in opposed relation, a supporting member therefor, a housing carried by said member provided with an opening at each end through which an end portion of an adjacent spring arm projects for sliding engagement with a surface on said supporting member, coil spring means under compression supported by said housing and arranged to bear on each of said slidable spring arm end portions to produce a frictional resistance to the sliding movements thereof, saidhousing providing means whereby compressive movements of said coil spring means is permitted and bodily movement thereof relative to said housing is prevented.

1S. In a bumper, a supporting member, a housing secured thereto, a supported spring member 2:)

having an end thereof projecting into said housing and adapted to have slidable movement therein, a rubber unit supported under compression within said housing and arranged in abutting normal relation to said spring member to produce a frictional resistance to the sliding movements thereof, and means associated with said housing and cooperating with said rubber unit to permit compressive movements of said rubber unit while preventing bodily movement thereof relative to t:

said h-ousing.

19. In a bumper, a main bar, a housing secured thereto, a back bar having an end thereof projecting into said housing for sliding engagement with a surface on said main bar, a rubber element 35 supported under compression within said housing, bearing means associated with one end of said rubber element and arranged to engage said back bar to produce a frictional resistance to the sliding movements thereof, said housing providing means for seating the other end of said rubber element, sai-d seating means being so constructed as to permit compressive movements of said rubber element and to prevent bodily movement thereof relative to said housing.

Z0. In a bumper comprising a pair of spring arms arranged in opposed relation, a supporting member therefor, a housing carried by said member provided with an opening at each end through which an end portion of an adjacent f spring arm projects for sliding engagement with a surface on said supporting member, a rubber block supported under compression arranged opposite each slidable spring arm end and engaging the same to produce a frictional resistance to the sliding and vibratory movements thereof, said housing providing means for seating said rubber blocks and so constructed and arranged as to permit compressive movements of said rubber blocks and to prevent bodily movement thereof relative to said housing.

21. In a bumper provided with a main bar, a back bar comprising a pair of spring arms, each spring arm being connected at least at one end to the main bar, housing means secured to the main bar, the other ends of said spring arms being each adapted to extend within said housing means for slidable frictional engagement with a surface on said main bar, spring means arranged within said housing means and adapted to normally bear on 70 back bar comprising a pair of spring arms, each 'l5 'spring arm being connected at one end to the main bar, the other ends of said spring arms being arranged in opposed relation for sliding engagement with a surface on said main bar, housing means arranged over the opposed ends of said spring arms Aand spring means within the housing means arranged to normally bear on the opposed spring arm ends to produce a frictional VILLOR P. WILLIAMS. 

